It is known to surface treat parts by passing the parts through a treating solution and U.S. Pat. Nos. 5,117,850 and 4,002,488 are representative examples thereof. During surface treatment, such as removing undesired surface characteristics from the parts, or such as coating, dyeing or chemically converting the surface of the parts, the parts usually move through a plurality of treatment stations, each containing a different chemical for treating the surfaces on the parts. A need exists for preventing a following chemical solution from contaminating the leading chemical solution.
Accordingly, it is an object of this invention to provide a surface treating device which allows parts to be treated to pass sequentially through a plurality of serially arranged treatment solutions arranged in a trough with appropriate treatment solution passageways being provided for continuously removing treatment solution with contaminants therein and with a dam being provided between each of the treatment solutions to keep the treatment solutions separated while simultaneously allowing the parts to move up and over the dam.
It is a further object of the invention to provide a surface treating device, as aforesaid, wherein the treatment solution is allowed to exit the trough solely through a wall defining the dam.
It is a further object of this invention to provide a surface treating device, as aforesaid, wherein the level of treatment solution in the surface treating portion of the device is controllable by adjustment of the volume of treatment solution entering the surface treating portion of the device.
It is a further object of the invention to provide a surface treating device, as aforesaid, wherein an elongated basin or trough is provided having a lowest end at one end and a dam at the other end, the dam including an inclined ramp extending from the lowest part of the trough to a top of the dam, both of the inclined ramp and the lowest part of the bottom wall supporting parts thereon which are allowed to travel from the lowest part toward the dam so that the parts can rise to a sufficient level in advance of clearance of the dam while simultaneously spraying treatment solution onto the parts and allowing the excess treatment solution to drain out of the trough through an adjustable fluid weir for regulating the volume of treatment solution exiting the trough and for simultaneously controlling the level of treatment solution in the trough.
It is a further object of the invention to provide a surface treatment device, as aforesaid, wherein the trough is annular and includes an outlet and a gate adjacent the outlet for diverting parts from moving toward a parts outlet and back into the trough and, in addition, wherein the trough includes an outer trough concentric with the inner trough, one end of the outer trough being oriented to receive parts exiting from a parts outlet from the inner trough for movement along a length of the outer trough toward an outlet chute at an end of the outer trough remote from the aforesaid one end.
It is a further object of the invention to provide a surface treatment device, as aforesaid, wherein the trough includes at least one treatment station along the length thereof so that parts moving along the trough will move through the treatment station and be treated by treatment solution thereat.
It is a still further object of the invention to provide a surface treatment device, as aforesaid, wherein the outer trough is composed of a plurality of connectable sections independent of the inner trough and adapted to be assembled as a unit.
It is a still further object of the invention to provide a surface treatment device, as aforesaid, wherein the level of treatment solution is regulatable to "cushion" the fall of parts moving over the dam.